Assertion: Isoelectronic ions have same number of electrons as well protons.
Reason: The number protons among the isoelectronic ions are different.

Options

A. Both A and B true and R is the correct explanation A
B. Both A and R are true but R is not a correct explanation of A
C. A is true but R is false
D. A is false but R is true

Answer

To solve the question, we need to analyze both the assertion and the reason provided.

### Step 1: Understand the Assertion
The assertion states that "Isoelectronic ions have the same number of electrons as well as protons."

- **Analysis**: Isoelectronic ions are ions that have the same number of electrons. However, they do not necessarily have the same number of protons. For example, consider the ions N³⁻, Ne, and F⁻. All three have 10 electrons, but they have different numbers of protons (N has 7 protons, Ne has 10 protons, and F has 9 protons).

### Step 2: Understand the Reason
The reason states that "The number of protons among the isoelectronic ions are different."

- **Analysis**: This statement is correct. As shown in the previous example, while isoelectronic ions have the same number of electrons, their proton counts vary. This is a defining characteristic of isoelectronic species.

### Step 3: Conclusion
Based on the analysis:
- The assertion is **false** because isoelectronic ions do not have the same number of protons.
- The reason is **true** as it correctly states that the number of protons among isoelectronic ions is different.

### Final Answer
- The assertion is false, and the reason is true. Therefore, the correct answer is that the assertion does not support the reason.

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